If you’ve been to any sort of SPL contest over the last few years, you’ll recognize the name Incriminator Audio. The company began in 2002 with the mission of breaking the mold 1that most car audio companies follow. When I asked company president, Nick Wright, what makes Incriminator Audio different, he said, “Our idea of a successful business is not the bottom line. While it’s important, it does not dictate what we define as success. A successful car audio manufacturer must create exceptional product on all levels – from quality to durability to customer satisfaction.”

The brand has built a strong reputation for rugged performance in extreme applications, and for innovation at a fair price without resorting to cookie cutter ways. They like to stand out from the crowd too. In today’s hype-filled, latest trend marketplace, Incriminator Audio’s motto is: “No chrome, no carbon fiber, no B.S. period!”

And to prove that they aren’t just into subwoofers and huge amplifiers, Nick sent us one of their new IA6.4 high performance full range, four channel amps. Let’s have a closer look.

Features

The new IA6.4 four-channel, full range Class D amplifier is quite compact when you consider it’s rather prodigious power rating. Rated at 100 x 4 at 4 ohms, and 150 x 4 at 2 ohms, the amp measures only 12” x 7” x 2.25”. The connections for power, ground and speakers are all made on one end of the chassis, with the signal input and control functions on the opposite end. The power and ground terminals accept 4 gauge wire, and all the other terminals will accept 8 gauge cables. The set screws use a Phillips style head, rather than the ubiquitous metric hex keys.

A pair of 25A ATC fuses provide protection from short circuits, although I found it interesting that the owner’s manual specifies a pair of 30A fuses. However, throughout my testing, the 25’s did not blow even once, so they are probably adequate. Also on the power panel end of the chassis is a blue power LED and a red protection LED.The opposite end of the amp is home to the RCA input connections, and all of the gain, signal steering and control adjustments.

A 2ch/4ch mode switch allows you to drive all the channels with a single pair of RCA’s, or have full balance and fader functionality by using the 4 channel mode. No need for Y splitters here. The crossover section of the amp uses separate controls for high pass and low pass function, and each section is also equipped with an x10 frequency multiplier button, which takes the 50-500Hz range to 500Hz-5kHz, for a truly flexible design. Filter slopes are fixed at -24dB/Oct. A subsonic filter featuring very wide range of adjustment (10-500Hz) is provided, and could help build a bandpass filter when used in conjunction with the high pass networks.

Of course, I had to have a look inside the IA6.4, and found an elaborate display of technology. As mentioned previously, the IA6.4 is a full range Class D design, and in these designs, parts tolerances and PCB layout are critical for a good sounding result. To control parts tolerance issues, the Incriminator Audio team chose to use 0% tolerance laser trimmed surface mount devices. These parts are much smaller in physical size than standard “through hole” parts. The smaller size allows for better layout solutions, and the choice of a double-sided PCB furnishes more room for high current carrying traces.

It was evident too, that Incriminator Audio intends these amps to last, as all of the high mass parts like transformers and output inductors are further secured with non-conductive silicone adhesive, which will reduce vibration induced failures.

The power supply draws energy from three 1000µF high-temp capacitors, and provides high voltage energy to a pair of 50V 4700µF electrolytics. All in all, pretty impressive inside!